How to shift a 5 and 4

Discussion in 'Questions From New Drivers' started by slim66, Oct 18, 2008.

  1. slim66

    slim66 Bobtail Member

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    There's one truck in our fleet with this transmission. There's been only two drivers I've known who knew how to drive this thing, both drivers absolutely loved driving it but would only give me vague answers on how it works or how to drive it and neither would let me drive with them to learn it. Now the truck sits in the yard. Call me insane but I really would like to learn this thing. Any hope here?
     
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  2. witchwaywest

    witchwaywest Medium Load Member

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    Back in the late 70's I worked for a stone yard.The boss had an old Diamond Reo with 5 by 4 trans.I was just a laborer not a driver but I give him credit for being able to shift that trans.He used to call it a sucide shift because he would drape his arm through the steering wheel to grab one stick and the other hand was shifting the other stick.Go to YouTube.There are a few videos on shifting twin sticks.Brought back memories.For the first one,type in the search box,(How to shift twin sticks)(B model Mack) and the second one,type in(1972 International 5 and 4 speed transmission shifting).I'm sure there's more but the B model Mack was close to what the Diamond Reo had.Let me know if this helps.
     
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  3. longbedGTs

    longbedGTs Heavy Load Member

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    I hear ya! Id love to take a shot at one of those twin sticks too!
     
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  4. heyns57

    heyns57 Road Train Member

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    I have driven only a B model with 5x2. However, I have the DVD "Trucks With 2 Sticks" from Long Road Productions. Ed Kite from Rocky Ford, CO, is one of the featured owners who demonstrates a truck on the DVD. He explains a 1956 LTL Mack with a 5 speed main transmission and a 4 speed deep under Spicer auxiliary.

    Deep under in the auxiliary is left and forward. You cannot shift out of deep under; it is only used off road. The other auxiliary gears are 3 speed progressive. That is, they are standard underdrive, direct, and overdrive. Start out with first gear in the main box and underdrive which is back to the left. Then shift the auxiliary to direct which is back to the right. Then shift the auxiliary forward to the right for overdrive. At that point, shift the main box to second and the auxiliary to underdrive, etc.

    Basically, when split shifting with both transmissions, the transmission to be upshifted is shifted first. The transmission to be downshifted is shifted second. Experts appear to shift both sticks almost simultaneously, but you do not want to get caught with both boxes in neutral if you miss both shifts.
     
    Last edited: Oct 18, 2008
  5. heyns57

    heyns57 Road Train Member

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    When downshifting the 5x4 on an upgrade, eliminate one gear combination out of the sequence if you are shifting both transmissions. There may not be enough time to float a split shift; so, skip a gear.

    Auxiliary transmissions have rows and rows of needle bearings, according to Ed Kite who taught truck driving at a junior college. Either 50 wt motor oil or 90 wt mineral oil is used in auxiliary transmissions. Never use all-purpose gear lube. Auxiliary transmissions must be warmed before driving. With the engine idling, place the main box in about third gear and the auxiliary in neutral to warm both transmissions.
     
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  6. longbedGTs

    longbedGTs Heavy Load Member

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    How many gears does a twin stick trans have? With so many combinations of gears for you to be in, Im guesing its near 20? Or...am I thinking wrong?
     
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  7. Johnny99

    Johnny99 <strong>Johnny be Good</strong>

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    I drove a Mack with a duplex and an old KW with a 4x4 trans in it. The 4x4 was basically 2 transmissions, a main and an auxiallry. To start out you put the main and the aux in 1st gear, then you shifted the aux, 1, 2 ,3, 4. Now comes the fun part. You steer with your knee, reach thru the steering wheel with your left arm and shift the main trans to 2nd while shifting the aux back to 1st with your right. then shift the aux 1,2,3,4 again. Keep repeating the process untill the main is in 4th and the aux is in 4th. To downshift you repeat the process in reverse. It can really get confusing if you forget which gear your in. The 4x4 was a 16 spd. The Mack duplex was a 5/2 that was a 9 spd. In high gear you didn't use the aux trans.
     
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  8. Drifter1948

    Drifter1948 Light Load Member

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    5x4 is a dood solid mechanical tranny no air to mess it up.
    Basically it is a 2 stick system, the stick closest to the seat is a5 speed (main) the furthest to the right is a 4 speed (auxillary)
    1st gear main, 1st gear aux release clutch your next 3 shifts are up shifts on aux to 4th. At this point you shift both sticks, main into 2nd, aux back to 1st and continue on up.next 3 shifts are up on aux. arriving in 4th on aux it again is time to shift both sticks Main into 3rd aux back to first.

    These gears are usually very close in ratio giving you a lot more power than speed. Feasably pulling a heavy load you could make 5 or 6 shifts across an intersection.

    Hope this makes it clearer than mud.
     
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  9. Drifter1948

    Drifter1948 Light Load Member

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    Johnny99 didn`t know you were replying also, Good answer to .
     
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  10. Johnny99

    Johnny99 <strong>Johnny be Good</strong>

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    I forgot about having to warm up the 4x4. The old KW had a thing, I forget what it was called, that looked like a mailbox flag. It moved up and down. When it went to the up position the trans was ok to go.
     
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